The shock absorber is mainly used to reduce the vibration output of a vibration source, thereby lowering the noise and reducing the shock on other parts. Most of common shock absorbers are rigid and non-adjustable, i.e. the inherent frequency of the shock absorber is constant and non-adjustable. In actual engineering application, the shock absorber with non-adjustable dynamic characteristics such as the rigidity frequency is always inconvenient to use. For example, the vibration characteristics of the large-sized equipment are highly related to the platform where the equipment is installed, so the original design index of the equipment cannot be achieved in actual use by adopting the rigidity non-adjustable shock absorber. The equipment is difficult to install and debug by assembling multiple groups of the shock absorbers with different rigidity specifications on site. Therefore, the shock absorber with adjustable dynamic characteristics such as the rigidity frequency aids in avoiding the above problem.
An adjustable shock absorber is disclosed in patent 201410169456.0, which is implemented by connecting the traditional elastic elements in parallel; and a plurality of groups of elastic elements and supporting modulators are required, so the cost is relatively high, the working rigidity of the shock absorber in this form cannot be continuously adjusted, and only the pre-set discrete working rigidity can be adjusted.
A composite shock absorber disclosed in patent 201410299504.8 has main defects as follows: (1) the rigidity adjusting unit adopts a magneto-rheological elastomer, thereby being complicated to control and relatively high in cost; (2) a mass adjusting unit adopts a liquid pump to change the liquid storage amount so as to change the mass, the response time of the adjusting unit is relatively long, and additional heavy parts such as a water storage tank is needed, which is not beneficial for the engineering use, and leads to the limited application range.
The shock absorber disclosed in the patent 201410462858.X has the main problem that the magneto-rheological elastomer way is used to adjust the rigidity, so the requirement for the control system is relatively high; and moreover, the overall cost is relatively high, and the application range is limited.